The present invention relates to an automatic fire hydrant water supplying system. More particularly, the present invention relates to an automatic fire hydrant water supplying system including an automatic hydrant flush valve for flushing debris from the standpipe (or barrel) of the hydrant, a remote-control hydrant supply valve for controlling the flow of water from the hydrant and an automatic air bleed valve for venting air from the fire hose supplying water to the master intake valve (MIV) of a fire truck pump and automatic refilling of the on-board water tank on the pumper fire truck.
In a typical fire scene scenario, as the pumper fire truck arrives at the fire scene, the pumper fire truck pauses at the nearest hydrant and a hydrant operator opens the hydrant to allow the initial flow of water to flush debris from the barrel and outlet of the hydrant. Thereafter, the hydrant operator attaches one end of a large-diameter, lay-flat (LDH) supply hose to the hydrant via an adapter or valve and remains at the hydrant to open the hydrant valve upon request as the pumper truck proceeds to the fire building laying out from the back of the truck the LDH supply hose.
Upon the pumper fire truck's arrival at the structure on fire, a fire truck pump operator immediately begins to pump water from the on-board water tank (or reservoir) onto the fire. As the water is being pumped from the on-board water tank, the other end of the LDH supply hose is connected to the intake valve of a fire pump (generally a centrifugal pump) on the fire truck. Once the hydrant valve is turned “On” and the hose is charged with water and bled of residual air, the pump intake valve is opened, supplying positive pressure directly to the inlet of the pump, and the speed on the fire pump is reduced to prevent an increase in discharge pressure, and the tank outlet valve controlling the flow of water from the on-board water tank is closed so that the fire pump is supplied with water from the hydrant and then the water tank on the truck is refilled.
When the lay-flat hose is initially charged with water, residual air entrapped in the hose is often pushed ahead of the water as the lay flat hose contains some air even when flat in storage on the fire truck. The trapped air must be removed to avoid loss of pressure and flow problems caused by a water hammer or by cavitation in the water pump.
Typically, removal of the air from the hose is accomplished with a manually operated valve upstream of the intake valve on the pump which may lead to problems. An operator may forget to open the manually operated air bleed valve.
As an alternative to the conventional practice of manually flushing the hydrant, manually opening the hydrant valve and manually bleeding air from the LDH supply hose, an automatic fire hydrant flush valve, a remote-controlled hydrant supply valve and an automatic air bleed valve integrated with the pumper fire truck pump control system for flushing debris from the hydrant, opening the hydrant supply valve and venting air from the fire hose supplying water to the master intake valve and filling the on board water tank of a fire truck without operator intervention is highly desirable.